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Many of the alterations that affect innate and adaptive immune cell compartments in HIV-infected patients are reminiscent of the process of immune aging, characteristic of old age. These alterations define the immunological age of individuals and are likely to participate to the decline of immune competence with HIV disease progression. It is therefore important to characterize these changes, which point toward the accumulation of highly differentiated immunocompetent cells, associated with overall telomere length shortening, as well as understanding their etiology, especially related to the impact of chronic immune activation. Particular attention should be given to the exhaustion of primary immune resources, including haematopoietic progenitors and naïve cells, which holds the key for effective hematopoiesis and immune response induction, respectively. The alteration of these compartments during HIV infection certainly represents the foundation of the immune parallel with aging. [ABSTRACT FROM AUTHOR]

Compared with HTV-1, HIV-2 infection is characterized by a larger proportion of slow or nonprogressors. A better understanding of HIV-2 pathogenesis should open new therapeutic avenues to establish control of HIV-1 replication in infected patients. In this study, we studied the production of CD8+ T cells and their capacity for viral control in HIV-2 controllers from the French ANRS C05 HIV-2 cohort. HIV-2 controllers display a robust capacity to support long-term renewal of the CD8+ T cell compartment by preserving immune resources, including hematopoietic progenitors and thymic activity, which could contribute to the long-term maintenance of the CD8+ T cell response and the avoidance of premature immune aging. Our data support the presence of HTV-2 Gag-specific CD8+ T cells that display an early memory differentiation phenotype and robust effector potential in HTV-2 controllers. Accordingly, to our knowledge, we show for the first time that HIV-2 controllers possess CD8+ T cells that show an unusually strong capacity to suppress HIV-2 infection in autologous CD4+ T cells ex vivo, an ability that likely depends on the preservation of host immune resources. This effective and durable antiviral response probably participates in a virtuous circle, during which controlled viral replication permits the preservation of potent immune functions, thus preventing HIV-2 disease progression. [ABSTRACT FROM AUTHOR]